§ 1033.315 Test procedures.
(a) Test procedures. Use the test procedures described in subpart F of this part, except as specified in this section.
(1) You may ask to use other test procedures. We will approve your request if we determine that it is not possible to perform satisfactory testing using the specified procedures. We may also approve alternate test procedures under § 1033.305(d).
(2) If you used test procedures other than those in subpart F of this part during certification for the engine family (other than alternate test procedures necessary for testing a development engine or a low hour engine instead of a low mileage locomotive), use the same test procedures for production line testing that you used in certification.
(b) Modifying a test locomotive. Once an engine is selected for testing, you may adjust, repair, maintain, or modify it or check its emissions only if one of the following is true: